Vertical coffee-mill



K. S. STENBO.

' VERTICAL coFFEE M|L L. APPLICATION FILED SEPT. 27, 1919.

Patented Apr. 13, 192.6.

UNITED sTATEs PATENT oEEioE.

KRISTEN SEVERIN STENBO, OF COPENHAGEN, DENMARK.

VERTICAL coEEEE-iviiLL.

Specification of Letters Patent.

Patented Apr. 13, 1920.

Application filed September 27, 1919. Serial No. 326,84.

is most convenient on account of the feedhopper and the flywheelnecessary in case of larger mills, when these are to be driven byhand-power.

iiywheels is not necessary, however, but they are retained nevertheless,mainly for advertising purposes in the so-called show-casecoEee-grinders Aof the kind` by which one or more mills are displayed,on a stand in the show-window' of the store, vtheir nickelplatedfiywheels, which are rotated together with the mill-axles, facing thestreet. This arrangement necessitates a considerable transmission, whichis partly placed within the show-case. i

In orderto attain a finer or coarser comi minution of the coffee in theheretofore used steel coffee-mills with conical grinding faces, themill-axle and the inner grinding member fixed thereon have been arrangedto be movable lengthwise, and adjustments of the iineness of thegrinding operation have been attained by pushingthe inner grindingmember farther intor or withdrawing Vit somewhat from the correspondingouter coniforin grinding-member. When coffee is present between the'grinding surfaces, the adjustment of the innergrinding-member fartherinto the outer one can only be effected while the axle is rotated.

In coffee-mills with horizontal grindingmembers, the lubricating oil mayforce its way into the coffee and moisten and pollute the same,especially when the oil-cups are well filled up.

The present invention has for its object to provide va steelcoifee-mill'with conical 'grinding-surfaces, of a construction' by whichthe desirable advertisingeffect may be retained, namely by rotation ofthe feedhopper, and whereby the provision of flywheels for advertisingpurposes and of the transmissions not required for the opera- `suchmills, Iat its upper end, the feed-hopper, so that tion of the mill maybe avoided. By the omission of the heavy flywheels and thetransmissions, any unnecessary wear on aXles and bearings will also beavoided, and the driving-power will be reduced.

The coffee is fed to the mill by way of the l vertical hollow mill-axleand is caught by an intermediate bottom above which there are providedholes giving the coffee access to the space between the two grindingmembers. zontally disposed, because this arrangement In order to retainthe advertising effect in the hollow mill-shaft supports,

the hopper is rotated together with the shaft. In engine-driven mills,the provision of The lubrication of the mill-shaft and of its bearing iseffected from an oil-chamber provided in-the interior of the bearing,the level ofthe inner wall of the said chamber being adjusted in suchv amanner, relatively to the outer wall of the bearing, that the Oil cannotflow over the said vwall and down to the grinding-surfaces.

One manner of constructing the invention is illustrated on the drawing,which shows 'a vertical section of a vertical motor-drivengrinding-mill.

1 is the mill-casing iitted with a plate 2, which is fastened to the topplate 3 of the stand and supports the motor 4. The shaft 5 of the latteris fitted with a worm 6 engaging a worm-wheel 7 on the mill-shaft 8 intothe top end whereof the feed-hopper 9 is screwed. The mill-shaft 8 isfitted with an outer cylinder 10 fitting into the bearing 'l1 of themill-casing, and an interior tube 12 to the bottom end whereof the innergrinding member 13 is fastened. This Igrinding-member is hollow and theupper portion thereof forms a chamber 16 limited at bottom by a convexpartition 14, there being provided, in the wall of the chamber,discharge holes 15 (only one of which is shown on the drawing) for thecolfee which slides from the hopper 9 by way of the tube 12 down intothe chamber 16 and thence, through the holes 15, out into thefunnelshaped space 17 between the top parts of the grinding members.

f 18 is the outer grinding member which is inserted in the mill-casing1, and is held in position there by a suitable pinching or tighteningdevice. The grinding member 18 is adjustable up and down in themill-casing by means of a bell-crank lever 19, which pivoted to themill-casing and whose lower, preferably forked-shaped, arm engages agroove or recess 2O on the outside of the grinding member 1S.

2l is a tube provided between the inner tube 12 of the shaft 8 and theouter cylinder 10 and firmly screwed to a flange 22 on the inside of themill-casing 1, against which fiange the lower edge of the cylinder 10bears, so that there is formed, between the tube 21 and the cylinder 10,a space 28 serving as an oil-chamber. From this chamber, the oil passes,by way of bores 24, out to the wearing surfaces on the cylinder 10 andthe bearing 1l. The uppermost bore 2li is located immediately above thetop edge of the bearing 1l, so that the oil, in case the chamber 23 isfilled to overflowing, will flow over the top edge of the bearing, thetop edge of the tube 21 being at a higher level than that of thebearing. Any excessive supply of oil is thereby prevented from flowingdown to the grinding surfaces.

Instead of the feed-hopper being vplaced in the upper end of themillshaft, it may be placed on a suitable frame on the plate 2, so thatit will be independent of they shaft and will not be rotated togetherwith the latter.

Having nnow particularly described and yascertained the nature of mysaid invention and in what manner the same is to be -performed, Ideclare that what I claim is l. A grinding mill, comprising acylindrical casing provided with an oil chamber concentric therewith, adouble-walled hollow shaft having its outer wall supported for :rotationwithin said chamber, a grind- `ing member secured to the inner wall ofsaid shaft and adapted to rotate therewith,

and a coperating grinding member secured within said casing.

2. A Igrinding mill, comprising a cylindrical casing provided with anoil chamber concentric therewith, a double-walled hol* low shaft havingits outer wall supported for rotation within said chamber, a grindingmember secured to the inner wall of said shaft and adapted :to rotatetherewith, said grinding member having va chamber in its upper end incommunication with said hollowshaft, and a cooperating grinding membersecured within said casing.

3. A grinding mill, comprising a cylindrical casing provided with an oilchamber 4concentric therewith, a double-walled hollow shaft having itsouter .wall supported for rotation within said chamber, `a grindingmember secured to the inner wall of said shaft, vand haying a chamber inits upper end -in communication with said shaft, and

la coperating grinding member ysecured said coperating grinding member,and the bottom of said chamber being so formed as to direct material. tobeground toward said openings.

4f. Steel coffee-mill comprising grinding members and a hollow verticalshaft, the hollow shaft being firmly connected at the bottom to one ofthe l grinding members which contains, at its upper end, a chamberclosed by an intermediate bottom adapted to catch the coffee droppingdown and to direct it sidewise toward the walls of the chamber, whereinthere are provided holes located immediately above the intermediatebottom and adapted to afford passage for the coffee to the grindingsurfaces, the hollow shaft supporting a cylinder being concentric withlthe axis of the shaft and resting in a bearing `in a mill-casing, therebeing provided vbetween the said cylinder and the wall of the hollowshaft a space, wherein there is inserteda tube adapted to form, incombination with the said cylinder, an oilchamber, the wall of the saidcylinder being perforated somewhat below the top edge of the said tube.

5. AA grinding mill, comprising a cylindrical casing kprovided withanoil-chamber concentric therewith, a hollow shaft, a cylinder supported-by said shaft concentric with the axis thereof for rotation within saidchamber, a grinding member secured to .the shaft and adapted to rotatetherewith, and a cooperating grinding member secured within said casing.

6. A grinding mill, comprising a cylindrical casing provided with an-oil chamber concentric therewith, -a hollow shaft, a cylinder supportedby said shaft `concentric with the axisfthereof Yfor rotation withinsaid 105 chamber, a grinding member secured to the shaft and adapted torotate therewith, said grinding member having a chamber in communicationwith the interior of the shaft, and a coperating grinding member secured110 with-in said casing.

7. A grinding mill, comprising .a cylindrical, casing provided with anoil chamber concentric therewith, a hollow shaft, a cylinder supportedby said shaft concentric with 115 the aXis thereof for rotation withinsaid chamber, a grinding member lsecured to the shaft and having achamber in communication with the interior of the shaft, and a to formin combination with said cylinder an oil chamber, the wall of the saidcylinder being perforated below the top edge of said tube, the top edgeof the mill casing being 15 below the top edge of said tube.

In testimony whereof I have signed my' name to this specification.

KRISTEN SEVERIN STENBO. Vitnesses:

i E. Wnmscow, V. BELMER.

